[string[]]$colors = "Black"   , "DarkBlue"   , "DarkGreen" , "DarkCyan",
                    "DarkRed" , "DarkMagenta", "DarkYellow", "Gray",
                    "DarkGray", "Blue"       , "Green"     , "Cyan",
                    "Red"     , "Magenta"    , "Yellow"    , "White"

for ($i = 0; $i -lt 64; $i++)
{
    for ($j = 0; $j -lt $colors.Count; $j++)
    {
        Write-Host (" " * 12) -BackgroundColor $colors[$j] -NoNewline
    }

    Write-Host
}